The chemistry and potential synthetic utility of cationic cobalt and iron complexes, (RC triple bond CCR2)Co2 (CO)6 ion (1) and (n3-allyl)Fe (CO)4 ion (2), are under investigation. Having previously demonstrated the facile, highly selective carbon-carbon bond-forming reactions of 1 with nucleophilic substrates including aromatics, beta-dicarbonyls, ketones, enol derivatives, and allylsilanes, we are attempting to extend these reactions to methyl- and aryl-metals, other silane derivatives, to develop annulation methodologies based on these alkylations, and to demonstrate their utility by effecting synthesis of selected natural products. Continued structural studies of 1 utilizing NMR spectroscopy, stereochemical studies, and x-ray diffraction are planned as well. Reactions of the iron species 2 with nucleophilic substrates such as aromatics, allyl silane and allyl nickel species, and enol derivatives are being examined as a synthetically attractive allylation and isoprenylation process.